Japan would be able to produce enough plutonium to make about 2,000 atomic bombs a year if a nuclear fuel reprocessing plant in the country's northeast goes into operation, a U.S. nuclear nonproliferation expert has warned.

Henry Sokolski, executive director at the Nonproliferation Policy Education Center, made the remark during a House Foreign Affairs Committee hearing Thursday, warning the opening of the Japanese reprocessing plant could prompt South Korea and China to take action in response.

Sokolski said it is "insulting to Seoul" and "reckless" for the U.S. government to allow Japan to reprocess nuclear fuel while banning South Korea from doing so through a bilateral nuclear cooperation agreement. Sokolski urged Congress to demand that the U.S. government renegotiate its nuclear cooperation pact with Tokyo.

The Rokkasho Nuclear Fuel Reprocessing Facility in the northeast prefecture of Aomori had originally been planned to begin operation in October last year, but its opening was delayed due to new safety regulations. Its operator said the plant would be ready for operation in October this year.

"If Japan ever decided to open its large reprocessing plant at Rokkasho, it would be producing roughly 2,000 bombs' worth of nuclear weapons-usable plutonium a year," Sokolski said. "This would almost certainly prompt South Korea to initiate nuclear enrichment or reprocessing of their own as a hedge or weapons option."

Sokolski said China could also take action in response, and whatever action it takes would "likely challenge not only Japan's and South Korea's security, but our own treaty commitment to defend our Asian allies."(Yonhap)